1/* $NetBSD: hmac.c,v 1.5 2017/10/05 09:59:04 roy Exp $ */ 2 3/*- 4 * Copyright (c) 2016 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Christos Zoulas. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31#include <sys/cdefs.h> 32__RCSID("$NetBSD: hmac.c,v 1.5 2017/10/05 09:59:04 roy Exp $"); 33 34#include <string.h> 35#include <stdlib.h> 36 37#include <md2.h> 38#include <md4.h> 39#include <md5.h> 40#include <rmd160.h> 41#include <sha1.h> 42#include <sha2.h> 43 44#define HMAC_SIZE 128 45#define HMAC_IPAD 0x36 46#define HMAC_OPAD 0x5C 47 48static const struct hmac { 49 const char *name; 50 size_t ctxsize; 51 size_t digsize; 52 size_t blocksize; 53 void (*init)(void *); 54 void (*update)(void *, const uint8_t *, unsigned int); 55 void (*final)(uint8_t *, void *); 56} hmacs[] = { 57 { 58 "md2", sizeof(MD2_CTX), MD2_DIGEST_LENGTH, MD2_BLOCK_LENGTH, 59 (void *)MD2Init, (void *)MD2Update, (void *)MD2Final, 60 }, 61 { 62 "md4", sizeof(MD4_CTX), MD4_DIGEST_LENGTH, MD4_BLOCK_LENGTH, 63 (void *)MD4Init, (void *)MD4Update, (void *)MD4Final, 64 }, 65 { 66 "md5", sizeof(MD5_CTX), MD5_DIGEST_LENGTH, MD5_BLOCK_LENGTH, 67 (void *)MD5Init, (void *)MD5Update, (void *)MD5Final, 68 }, 69 { 70 "rmd160", sizeof(RMD160_CTX), RMD160_DIGEST_LENGTH, 71 RMD160_BLOCK_LENGTH, 72 (void *)RMD160Init, (void *)RMD160Update, (void *)RMD160Final, 73 }, 74 { 75 "sha1", sizeof(SHA1_CTX), SHA1_DIGEST_LENGTH, SHA1_BLOCK_LENGTH, 76 (void *)SHA1Init, (void *)SHA1Update, (void *)SHA1Final, 77 }, 78 { 79 "sha224", sizeof(SHA224_CTX), SHA224_DIGEST_LENGTH, 80 SHA224_BLOCK_LENGTH, 81 (void *)SHA224_Init, (void *)SHA224_Update, 82 (void *)SHA224_Final, 83 }, 84 { 85 "sha256", sizeof(SHA256_CTX), SHA256_DIGEST_LENGTH, 86 SHA256_BLOCK_LENGTH, 87 (void *)SHA256_Init, (void *)SHA256_Update, 88 (void *)SHA256_Final, 89 }, 90 { 91 "sha384", sizeof(SHA384_CTX), SHA384_DIGEST_LENGTH, 92 SHA384_BLOCK_LENGTH, 93 (void *)SHA384_Init, (void *)SHA384_Update, 94 (void *)SHA384_Final, 95 }, 96 { 97 "sha512", sizeof(SHA512_CTX), SHA512_DIGEST_LENGTH, 98 SHA512_BLOCK_LENGTH, 99 (void *)SHA512_Init, (void *)SHA512_Update, 100 (void *)SHA512_Final, 101 }, 102}; 103 104static const struct hmac * 105hmac_find(const char *name) 106{ 107 for (size_t i = 0; i < __arraycount(hmacs); i++) { 108 if (strcmp(hmacs[i].name, name) != 0) 109 continue; 110 return &hmacs[i]; 111 } 112 return NULL; 113} 114 115ssize_t 116hmac(const char *name, 117 const void *key, size_t klen, 118 const void *text, size_t tlen, 119 void *digest, size_t dlen) 120{ 121 uint8_t ipad[HMAC_SIZE], opad[HMAC_SIZE], d[HMAC_SIZE]; 122 const uint8_t *k = key; 123 const struct hmac *h; 124 uint64_t c[32]; 125 void *p; 126 127 if ((h = hmac_find(name)) == NULL) 128 return -1; 129 130 131 if (klen > h->blocksize) { 132 (*h->init)(c); 133 (*h->update)(c, k, (unsigned int)klen); 134 (*h->final)(d, c); 135 k = (void *)d; 136 klen = h->digsize; 137 } 138 139 /* Form input and output pads for the digests */ 140 for (size_t i = 0; i < sizeof(ipad); i++) { 141 ipad[i] = (i < klen ? k[i] : 0) ^ HMAC_IPAD; 142 opad[i] = (i < klen ? k[i] : 0) ^ HMAC_OPAD; 143 } 144 145 p = dlen >= h->digsize ? digest : d; 146 if (p != digest) { 147 memcpy(p, digest, dlen); 148 memset((char *)p + dlen, 0, h->digsize - dlen); 149 } 150 (*h->init)(c); 151 (*h->update)(c, ipad, (unsigned int)h->blocksize); 152 (*h->update)(c, text, (unsigned int)tlen); 153 (*h->final)(p, c); 154 155 (*h->init)(c); 156 (*h->update)(c, opad, (unsigned int)h->blocksize); 157 (*h->update)(c, digest, (unsigned int)h->digsize); 158 (*h->final)(p, c); 159 160 if (p != digest) 161 memcpy(digest, p, dlen); 162 163 return (ssize_t)h->digsize; 164} 165